If an opponent gains control of one of your creatures, that creature phases out, and the duration of the control-change effect expires before it phases back in, that creature phases in under your control as that opponent's next untap step begins
Amber brings healing and supportive characters that allow you to recover from early aggression, while Amethyst adds tricky control tools that can block, bounce, or stall your opponents biggest threats
Basically, its hard to kill, and works well in decks that enjoy dealing damage with spells
Thanks for coming along
Pokemon TCG, since its inception in 1996, has been a whirlwind journey of nostalgia, strategy, and, of course, the thrill of the hunt for the rarest cards